Radio communication systems are known to include fixed infrastructure networks and mobile or portable radio communication units. One such radio communication system is a cellular communication system. In cellular communication systems, the fixed infrastructure network typically includes a plurality of base sites, a base site controller (BSC), and a mobile switching center (MSC). Each base site provides communication service to a respective service coverage area generally referred to as a cell. The geographic size of each cell is determined theoretically prior to system installation by system designers and is generally established by the height placement of the base site antenna and the output power of the base site transmitters. In some cellular systems, base monitor radios (actually portable radio communication units) are included at each base site to monitor the output power of the respective base site in order to insure that the output power does not exceed the theoretically-determined maximum.
As noted above, system designers determine base site antenna height and base site output power to provide satisfactory communication service to a particular service coverage area. Such calculations are typically based on measured propagation losses for the system. To measure propagation losses, the system designers set up a test system in the desired geographical area of the actual system and measure the signal strength of received test signals in accordance with known techniques. However, such propagation measurements are generally performed during normal weather conditions for the area (e.g., partly sunny day with moderate humidity) and, depending on what time of year and in what portion of a particular country the measurements are made, may not include the effects of changes in terrain, such as fully-bloomed or snow-covered trees or a newly-constructed building. Consequently, when changes in weather conditions or terrain occur, so-called "holes" or "gaps" in communication service may result in a cell due to greater than expected propagation losses caused by the change in weather or terrain.
Therefore, a need exists for a radio communication system and method of setting an output power of a base site therein that provides dynamic adjustment of base site output power to take into account changing weather and terrain conditions, thereby providing improved communication service to users in the system.